Liu Yu, Yang Dongqi, Zhao Yuanchun, Yang Yanqiu, Wu Shiwei, Wang Jing, Xia Lixin, Song Peng
College of Chemistry, Liaoning University, Shenyang 110036, China.
Experimental Center of Shenyang Normal University, Shenyang 110034, China.
Heliyon. 2019 Apr 28;5(4):e01545. doi: 10.1016/j.heliyon.2019.e01545. eCollection 2019 Apr.
A large number of literatures have investigated the selective photocatalytic reaction of 4-aminothiophenol (PATP) to p,p'-dimercaptoazobenzene (DMAB). Most of them mainly study the contribution of substrate, excitation wavelength, exposure time, pH and added cations to plasmon-assisted surface catalytic reactions. However, we mainly study focuses on the effects of solvents on the dimerization of PATP to DMAB under the action of Ag nanoparticles (NPs). In experiments, a variety of diols was selected as solvents for the probe molecule PATP, and power-dependent SERS spectra were obtained at an excitation wavelength of 532 nm. From the laser-dependent SERS spectrum, we found that the characteristic peak enhancement effect of the product DMAB in different solvents is significantly different. That is, different solvents could regulate the rate at which DMAB is produced from PATP. Based on the experimental results, we further explored how different diol solvents regulate the response of PATP to DMAB. Our conclusion is that the solvent in the system can quickly capture the hot electrons generated by the decay of the plasmon, so that the remaining holes can oxidize PATP to form DMAB. The ability to trap hot electrons is different due to the difference in the position of the functional groups in the solvent, so that the photocatalytic reaction rate of the hole-oxidized PATP is different. The ability to capture electrons varies depending on the position of the functional groups in the solvent, so the oxidation rate of the photocatalytic reaction is also different. This work not only deepens our understanding of the mechanism of hole-driven surface catalysis oxidation reaction, but also provides a convenient method for regulating the rate of catalytic oxidation.
大量文献研究了4-氨基苯硫酚（PATP）选择性光催化反应生成对，对'-二巯基偶氮苯（DMAB）。其中大多数主要研究底物、激发波长、曝光时间、pH值和添加阳离子对等离子体激元辅助表面催化反应的贡献。然而，我们的主要研究重点是在银纳米颗粒（NPs）作用下，溶剂对PATP二聚生成DMAB的影响。实验中，选择了多种二醇作为探针分子PATP的溶剂，并在532nm激发波长下获得了功率依赖的表面增强拉曼光谱（SERS）。从激光依赖的SERS光谱中，我们发现产物DMAB在不同溶剂中的特征峰增强效应有显著差异。也就是说，不同溶剂可以调节PATP生成DMAB的速率。基于实验结果，我们进一步探究了不同二醇溶剂如何调节PATP对DMAB的响应。我们的结论是，体系中的溶剂能够快速捕获等离子体激元衰减产生的热电子，使得剩余的空穴能够氧化PATP形成DMAB。由于溶剂中官能团位置的差异，捕获热电子的能力不同，从而使得空穴氧化PATP的光催化反应速率不同。捕获电子的能力因溶剂中官能团位置的不同而有所变化，所以光催化反应的氧化速率也不同。这项工作不仅加深了我们对空穴驱动表面催化氧化反应机理的理解，还提供了一种调节催化氧化速率的简便方法。
